Clinical and urodynamic outcomes in children with anorectal malformation subtype of recto-bladder neck fistula

Abstract

Patients with anorectal malformations (ARMs) have a high incidence of genitourinary anomalies. Those with a recto-bladder neck fistula may represent a high-risk group, but their long-term urologic outcomes are poorly described. To evaluate the clinical and urodynamic outcomes in a large cohort of patients with an ARM subtype of recto-bladder neck fistula. A retrospective cohort study was performed of patients who had been treated for a recto-bladder neck fistula at the present institution since 2007. The primary outcomes were the ability to achieve urinary continence after 4 years of age, and development of a mildly decreased glomerular filtration rate (GFR) or worse (<89ml/min/1.73m2). Continence was defined as the ability to store urine for 3-4h during the day and 8h overnight without leakage. Demographic and clinical data are provided in the Summary Table. The most recent urodynamic findings included the presence of detrusor overactivity in 30 (75%) patients, median leak point pressure of 56.0cmH2O (range, 14-140), median functional cystometric capacity at 40cmH2O of 125.5% age-expected capacity (range, 36-473%), and median maximum cystometric capacity of 131.0% age-expected capacity (range, 44-473%). A mildly decreased GFR or worse developed in 13 (24%) patients. Of the 52 (78%) patients who were followed by pediatric urology at the present institution with a median follow-up of 30.9 months (range, 0.0-86.8), 35 (67%) were at least 4 years of age and could be assessed for continence. Continence was achieved in five (14%) patients voiding spontaneously and 15 (43%) performing CIC. Recurrent urinary tract infections (UTI) (OR 0.70, P=0.006) were an independent predictor of incontinence, while urethral anomalies (OR 1.40, P=0.03) were an independent predictor of chronic kidney disease (CKD) on multiple logistic regression analysis. The findings favorably compared with other studies, but were more robust due to the size of the cohort and breadth of urologic evaluation. Limitations included the retrospective design at a single institution. Incomplete clinical data and misclassification of continence may have lead to bias. This large cohort of patients with an ARM subtype of recto-bladder neck fistula had a high incidence of genitourinary anomalies. They were rarely able to achieve continence with spontaneous voiding alone and were at risk of developing CKD, both of which were likely multifocal in origin. Long-term urologic follow-up is warranted for patients with a recto-bladder neck fistula.